In order to evolve Eevee into a Jolteon you need to have the thunderstone in your bag, select "use" and then select your Eevee from your Party. You can't evolve it by making it hold onto the Thunder stone.
You give it a thunderstone
you can catch a Eevee then use a thunder stone to evolve it into Jolteonyou can trade ityou can migrate a shiny over lv. 100 jolteon
it is impossible to get one. the only way is to get an eevee from bebe in hearthome and use an thunder stone!
In your bag, just select the Thunderstone and pick the "use" option, then choose Eevee (who must be in your party) to evolve it.
you need the thuderstone and nat dex give eevee thunderstone and vola
A Thunder Stone is a stone that can make some electric types evolve. Such as if ypu use it on a Pikachu it will evolve into a Richu and if you use it on a eevee it will become a Jolteon!
use a firestone on eevee
You use a water stone on your Eevee.
Pikachu-Raichu Eevee- Jolten
You can evolve your Eevee into Glaceon
A Flareon
eevee does only evolve into glaceon in dimond, pearl, platinum ss and hg